We’ve discussed many times how compressing air generates free water and water vapor in the compressor tank and in the air lines. What happens if a line goes outside?
If your air compressor is in the sub tropics or tropics….nothing special.
If you happen to be in northern latitudes however, there’s a real likelihood that the water that’s getting into your air lines, where those air lines exit a warm building to travel to another through exposed winter time temperatures, will freeze. Get enough of it in the lines, and it will freeze solid and block your air line.
Sometimes you cannot help but have an air line go outside to get to another location, and if you are one of the unfortunate folks that lives where the air freezes, here’s what you can do.
First choice…run a heater wire the exposed length of the air line, and then insulate it so that the temperature in the line doesn’t get below freezing. Be prepared to have a lot of water traveling along that line, so have a drop leg with an auto drain where the line re-enters a warm building.
Next choice…reduce the dew point of the compressed air just before it leaves the warm building so that the dew point of the air entering the cold line outside is well below the lowest temperature that the compressed air might experience as it traverses the outside air line. If the air is dry enough, there won’t be any water in the air to freeze, and you won’t have a problem. Warning, this is an expensive and maintenance prone solution.
Last…don’t do it! Determine the requirements of compressed air in the building to which the exposed air line was traveling, and install a compressor there to supply that part of your operation.